Cathode-ray tube.



H. E. R. RUKOP & W. K. M. SCHLOEMILCH.

CATHODE RAY TUBE.

APPLlCATlON FILED OCT. 28. 1915.

Patented Jan. 2, 1917.

HANS EWALD REINHOLD BUKOP AND WILHELM KUNO MAX SCHLOEMILCE, 0F BERLIN,GERMANY, ASSIGNORS TO GESELLSCHAFT FI I IR DRA'HTLOSE TELEGRAI'HIEM.-IB.-H., 0F BERLIN, GERMANY, A COBPQBATION OF GERMANY.

oa'rnonn-nar TUBE.

Specification of Letters Patent.

Patented Jan. 2, 1%

To all whom it may concern;

Be it known that we, HANs' EWALD REIN- HOLD Honor and WInHELM Keno MAXSGHLOEMILCH, subjects of the German Emperor, and residing at Berlin,Germany, have invented certain new and useful Improvements inCathode-Ray Tubes, of which the following is a specification.

Our invention relates to cathode ray tubes which do not work withdiluted gases but, as pure electron tubes, under a high vacuum and inwhich in addition to the anode a special auxiliary anode is provided.Cathode ray tubes of this kind are employed as amplifying relays,generators of oscillations or the like. Experience has shown that, forproducing the most favorable effects with tubes of the class referredto, the

mode of arrangement of the heating cathode as well as its distance fromthe auxiliary anode are important. Certain difiiculties have beenexperienced from tubes of this class by reason of the mode of arrangingthe glowing cathode relatively to the auxiliary anode as heretoforeemployed. In manufacture, for instance, it was difiicult to maintain thenecessary small distance between the electrodes; in operation variationsof the distance of the electrodes were encountered.

The object of the present invention is to obviate such difiiculties.

According to the present invention the heating wire of the cathodetogether with its conductor are arranged at right angles to the planearrangement of the heating cathode has the advantage that in manufacturethe heating wire may be located in the direct proximity of the auxiliaryanode without exposing the construction to a short circuit between theelectrodes. Lateral oscillations of the heating cathode do not efiect achange of the distance between the heating cathode and the auxiliaryanode. Thus, the o eration will not be interrupted thereby. oreover, theefiiciency of the cathode is materially increased as compared with thearrangements heretofore employed. The construction of the glowingcathode is immaterial to the invention. he glowing wire may be shaped inthe form of a simple loop or of a spiral. For operating the tube withalternating current of high frequency it is preferable to provide aglowing cathode consisting of sevof the auxiliary anode. This eralheating wires connected in parallel. Such glowing cathodes are suitablefor very high loads and for tubes which are employed for generatingoscillations. It is also preferable to surround the glowing cathode witha screen device at those portions which are not opposite the auxiliaryanode. By the screen device the electrons laterally emitted from theglowing cathode are prevented from heating the glass wall of the tube.If a potential, 6. 9., that of the glowing cathode or a higherpotential, is applied to the screen device, which preferably con sistsof metal, this will have the favorable action that the electrons hittingthe screen device will be reflected, thus strengthening the stream ofelectrons to the anode.

Several constructional forms of the tube in elevation and section areshown in the accompanying drawing. I

In the arrangement according to Fig. 1, 1 is the glass body of the tubeand 2 the filament of the cathode forming a simple loop which isconnected with the conductors 3. According to the invention the filament2 with its conductors 3 is arranged at right angles to the plane of theauxiliary anode 4. The latter is formed by a metallic spiral (see Fig.2) which is stiffened by a glass rod 5 and thereby rigidly connectedwith the anode 6 consisting of a metallic disk, thus forming aself-sustaining body. 7 and 8 are the conductors to the anode andauxiliary anode.

Instead of employing as a filament a single wire 2 bent to a loop,several wires connected in parallel may be provided, as shown in Fig. 3.This construction is especially adapted for amplifying alternatingcurrents of high frequency. It also allows the use of considerablyhigher tensions for the filament than the simple constructional formshown in Fig. 1, and is, therefore, especially adapted for tubesemployed for generating oscillations.

It is evident that the arrangement of the filament at right angles tothe auxiliary anode facilitates in manufacture the maintenance of adefinite small distance between tance between'the parallel electrodescould l i l only be attained with great skill of the glass blower. Inthe manufacture of the tube according to the present invention theinsertion of the heating body and of the anode by fusing the glasssupports is just as simple as the insertion of the filaments into anordinary incandescent lamp.

With a view to preventing the electrons emitted laterally of the glowingcathode from damaging the adjacent glass wall of the tube a cone shapedscreen 9 is provided forming a jacket and being supported by arms 11 ofthe glass body. This screen may consist of insulating material as glassor the like, or of metal and may have other suitable forms than thoseshown. If a metallic screenis employed, it is preferable to conmeet itby a conductor 12 with a source of energy. The conductor may be directlyconnected with the potential of the glowing cathode or a higherpotential may be applied to it. By the potential thus applied to thescreen the electrons hitting the screen are reflected and serve forstrengthening the stream of electrons flowing to the auxiliary anode.

Experiments have proven that the lateral radiation of heat and emissionof electrons is particularly violent in certain directions dependingupon the shape of the glowing cathode. It is, therefore, not necessaryto extend the screen or jacket around the whole glowing cathode, but itis suflicient to provide smaller screens at the portions having the mostintense lateralradiation. An arrangement of this kind is shown in Fig.4.

By arranging the glowingv cathode with its conductors at right angles tothe plane of a the auxiliary anode the manufacture of such tubes ismaterially simplified. In manufacture it is preferable to employ a tubehaving two openings opposite each other. Into the openings plugs are.fused one of which, for instance that in the bottom, serves as a supportfor the anode and the auxiliary anode, whereas the other at the top,serves as a support for the glowing cathode. This construction will alsobe apparent from Fig. 4. In this figure, 1 is the glass body of thetube. The bottom part 13 supports the auxiliary anode 4 and the anode 6which are both kept a certain distance apart by the glass support 14.The cover 15 and the glass yoke 16 connected therewith serve as asupport for the glowing cathode2 and the two laterally arranged screens17 It is evident, that by this mode of construction the manufacture ofthe cathode tube is materially simplified. Thus, the cover may beexactly adj usted and the filament located very closely to the grid 4.

Claims:

1. In a cathode ray tube having a high vacuum, an anode, an auxiliaryanode, insulating blocks connecting said anode with said auxiliaryanode, and a glowing cathode perpendicularly arranged to the plane ofsaid auxiliary anode.

2. In a cathode ray tube having a high vacuum, an anode, a spiralforming an auxiliary anode, stiffening means for said auxiliary anode,and a glowing cathode perpendicularly arranged to the plane of saidspiral.

3. In combination a glass tube, an anode and an auxiliary anode therein,a common support for said anode and auxiliary anode, attached to saidtube, a glowing cathode perpendicularly arranged to the plane of saidauxiliary anode and supporting means for said cathode independently ofsaid common support.

4. In combination, a glass tube, an anode, an auxiliary anode therein, acommon su port for said anode and said auxiliary anode forming thebottom part of said tube, a glowing cathode perpendicularly arranged tothe plane of said auxiliary anode and supported by a block forming thecover of said tube.

5. In combination, a glass tube, an anode, an auxiliary anode therein, acommon support for said anode and said auxiliary anode forming thebottom part of said tube, a glowing cathode perpendicularly arranged tothe plane of said auxiliary anode and supported by a block forming thecover of said tube, and means for strengthening the stream of electronsfrom saidcathode to said anode.

In testimony whereof we affix our signatures in the presence oftwowitnesses.

DB. HANS EWALD REINHOLD RUKOP. WILHELM KUNO MAX SCHLOEMILCH. Witnesses:

HENRY HASPER, ARTHUR Sermononn.

